[embedder] embedder external view adopt DisplayListEmbedderViewSlice

ci/licenses_golden/excluded_files

@@ -207,6 +207,7 @@
 ../../../flutter/shell/common/animator_unittests.cc
 ../../../flutter/shell/common/canvas_spy_unittests.cc
 ../../../flutter/shell/common/context_options_unittests.cc
+../../../flutter/shell/common/dl_op_spy_unittests.cc
 ../../../flutter/shell/common/engine_unittests.cc
 ../../../flutter/shell/common/fixtures
 ../../../flutter/shell/common/input_events_unittests.cc

ci/licenses_golden/licenses_flutter

@@ -2107,6 +2107,8 @@ ORIGIN: ../../../flutter/shell/common/display.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/common/display.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/common/display_manager.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/common/display_manager.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/common/dl_op_spy.cc + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/common/dl_op_spy.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/common/engine.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/common/engine.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/common/pipeline.cc + ../../../flutter/LICENSE
@@ -4689,6 +4691,8 @@ FILE: ../../../flutter/shell/common/display.cc
 FILE: ../../../flutter/shell/common/display.h
 FILE: ../../../flutter/shell/common/display_manager.cc
 FILE: ../../../flutter/shell/common/display_manager.h
+FILE: ../../../flutter/shell/common/dl_op_spy.cc
+FILE: ../../../flutter/shell/common/dl_op_spy.h
 FILE: ../../../flutter/shell/common/engine.cc
 FILE: ../../../flutter/shell/common/engine.h
 FILE: ../../../flutter/shell/common/pipeline.cc

display_list/dl_blend_mode.h

@@ -9,8 +9,7 @@ namespace flutter {
 
 /// A enum define the blend mode.
 /// Blends are operators that take in two colors (source, destination) and
-/// return a new color. Blends are operators that take in two colors (source,
-/// destination) and return a new color. Many of these operate the same on all 4
+/// return a new color. Many of these operate the same on all 4
 /// components: red, green, blue, alpha. For these, we just document what
 /// happens to one component, rather than naming each one separately. Different
 /// color types might have different representations for color components:

flow/embedded_views.cc

@@ -30,6 +30,18 @@ void DisplayListEmbedderViewSlice::render_into(DlCanvas* canvas) {
   canvas->DrawDisplayList(display_list_);
 }
 
+void DisplayListEmbedderViewSlice::dispatch(DlOpReceiver& receiver) {
+  display_list_->Dispatch(receiver);
+}
+
+bool DisplayListEmbedderViewSlice::is_empty() {
+  return display_list_->bounds().isEmpty();
+}
+
+bool DisplayListEmbedderViewSlice::recording_ended() {
+  return builder_ == nullptr;
+}
+
 void ExternalViewEmbedder::SubmitFrame(GrDirectContext* context,
                                        std::unique_ptr<SurfaceFrame> frame) {
   frame->Submit();

flow/embedded_views.h

@@ -352,6 +352,9 @@ class DisplayListEmbedderViewSlice : public EmbedderViewSlice {
   std::list<SkRect> searchNonOverlappingDrawnRects(
       const SkRect& query) const override;
   void render_into(DlCanvas* canvas) override;
+  void dispatch(DlOpReceiver& receiver);
+  bool is_empty();
+  bool recording_ended();
 
  private:
   std::unique_ptr<DisplayListBuilder> builder_;

shell/common/BUILD.gn

@@ -77,6 +77,8 @@ source_set("common") {
     "display.h",
     "display_manager.cc",
     "display_manager.h",
+    "dl_op_spy.cc",
+    "dl_op_spy.h",
     "engine.cc",
     "engine.h",
     "pipeline.cc",
@@ -287,6 +289,7 @@ if (enable_unittests) {
       "animator_unittests.cc",
       "canvas_spy_unittests.cc",
       "context_options_unittests.cc",
+      "dl_op_spy_unittests.cc",
       "engine_unittests.cc",
       "input_events_unittests.cc",
       "persistent_cache_unittests.cc",

shell/common/dl_op_spy.cc

@@ -0,0 +1,138 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/shell/common/dl_op_spy.h"
+
+namespace flutter {
+
+bool DlOpSpy::did_draw() {
+  return did_draw_;
+}
+
+void DlOpSpy::setColor(DlColor color) {
+  if (color.isTransparent()) {
+    will_draw_ = false;
+  } else {
+    will_draw_ = true;
+  }
+}
+void DlOpSpy::setColorSource(const DlColorSource* source) {
+  if (!source) {
+    return;
+  }
+  const DlColorColorSource* color_source = source->asColor();
+  if (color_source && color_source->color().isTransparent()) {
+    will_draw_ = false;
+    return;
+  }
+  will_draw_ = true;
+}
+void DlOpSpy::save() {}
+void DlOpSpy::saveLayer(const SkRect* bounds,
+                        const SaveLayerOptions options,
+                        const DlImageFilter* backdrop) {}
+void DlOpSpy::restore() {}
+void DlOpSpy::drawColor(DlColor color, DlBlendMode mode) {
+  did_draw_ |= !color.isTransparent();
+}
+void DlOpSpy::drawPaint() {
+  did_draw_ |= will_draw_;
+}
+// TODO(cyanglaz): check whether the shape (line, rect, oval, etc) needs to be
+// evaluated. https://github.com/flutter/flutter/issues/123803
+void DlOpSpy::drawLine(const SkPoint& p0, const SkPoint& p1) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawRect(const SkRect& rect) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawOval(const SkRect& bounds) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawCircle(const SkPoint& center, SkScalar radius) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawRRect(const SkRRect& rrect) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawDRRect(const SkRRect& outer, const SkRRect& inner) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawPath(const SkPath& path) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawArc(const SkRect& oval_bounds,
+                      SkScalar start_degrees,
+                      SkScalar sweep_degrees,
+                      bool use_center) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawPoints(PointMode mode,
+                         uint32_t count,
+                         const SkPoint points[]) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawVertices(const DlVertices* vertices, DlBlendMode mode) {
+  did_draw_ |= will_draw_;
+}
+// In theory, below drawImage methods can produce a transparent screen when a
+// transparent image is provided. The operation of determine whether an image is
+// transparent needs examine all the pixels in the image object, which is slow.
+// Drawing a completely transparent image is not a valid use case, thus, such
+// case is ignored.
+void DlOpSpy::drawImage(const sk_sp<DlImage> image,
+                        const SkPoint point,
+                        DlImageSampling sampling,
+                        bool render_with_attributes) {
+  did_draw_ = true;
+}
+void DlOpSpy::drawImageRect(const sk_sp<DlImage> image,
+                            const SkRect& src,
+                            const SkRect& dst,
+                            DlImageSampling sampling,
+                            bool render_with_attributes,
+                            SrcRectConstraint constraint) {
+  did_draw_ = true;
+}
+void DlOpSpy::drawImageNine(const sk_sp<DlImage> image,
+                            const SkIRect& center,
+                            const SkRect& dst,
+                            DlFilterMode filter,
+                            bool render_with_attributes) {
+  did_draw_ = true;
+}
+void DlOpSpy::drawAtlas(const sk_sp<DlImage> atlas,
+                        const SkRSXform xform[],
+                        const SkRect tex[],
+                        const DlColor colors[],
+                        int count,
+                        DlBlendMode mode,
+                        DlImageSampling sampling,
+                        const SkRect* cull_rect,
+                        bool render_with_attributes) {
+  did_draw_ = true;
+}
+void DlOpSpy::drawDisplayList(const sk_sp<DisplayList> display_list,
+                              SkScalar opacity) {
+  if (did_draw_ || opacity == 0) {
+    return;
+  }
+  DlOpSpy receiver;
+  display_list->Dispatch(receiver);
+  did_draw_ |= receiver.did_draw();
+}
+void DlOpSpy::drawTextBlob(const sk_sp<SkTextBlob> blob,
+                           SkScalar x,
+                           SkScalar y) {
+  did_draw_ |= will_draw_;
+}
+void DlOpSpy::drawShadow(const SkPath& path,
+                         const DlColor color,
+                         const SkScalar elevation,
+                         bool transparent_occluder,
+                         SkScalar dpr) {
+  did_draw_ |= !color.isTransparent();
+}
+
+}  // namespace flutter

shell/common/dl_op_spy.h

@@ -0,0 +1,109 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_DISPLAY_LIST_DL_OP_SPY_H_
+#define FLUTTER_DISPLAY_LIST_DL_OP_SPY_H_
+
+#include "flutter/display_list/dl_op_receiver.h"
+#include "flutter/display_list/utils/dl_receiver_utils.h"
+
+namespace flutter {
+
+//------------------------------------------------------------------------------
+/// Receives to drawing commands of a DisplayListBuilder.
+///
+/// This is used to determine whether any non-transparent pixels will be drawn
+/// on the canvas.
+/// All the drawImage operations are considered drawing non-transparent pixels.
+///
+/// To use this class, dispatch the operations from DisplayList to a concrete
+/// DlOpSpy object, and check the result of `did_draw` method.
+///
+/// ```
+///    DlOpSpy dl_op_spy;
+///    display_list.Dispatch(dl_op_spy);
+///    bool did_draw = dl_op_spy.did_draw()
+/// ```
+///
+class DlOpSpy final : public virtual DlOpReceiver,
+                      private IgnoreAttributeDispatchHelper,
+                      private IgnoreClipDispatchHelper,
+                      private IgnoreTransformDispatchHelper {
+ public:
+  //----------------------------------------------------------------------------
+  /// @brief      Returns true if any non transparent content has been drawn.
+  bool did_draw();
+
+ private:
+  void setColor(DlColor color) override;
+  void setColorSource(const DlColorSource* source) override;
+  void save() override;
+  void saveLayer(const SkRect* bounds,
+                 const SaveLayerOptions options,
+                 const DlImageFilter* backdrop) override;
+  void restore() override;
+  void drawColor(DlColor color, DlBlendMode mode) override;
+  void drawPaint() override;
+  void drawLine(const SkPoint& p0, const SkPoint& p1) override;
+  void drawRect(const SkRect& rect) override;
+  void drawOval(const SkRect& bounds) override;
+  void drawCircle(const SkPoint& center, SkScalar radius) override;
+  void drawRRect(const SkRRect& rrect) override;
+  void drawDRRect(const SkRRect& outer, const SkRRect& inner) override;
+  void drawPath(const SkPath& path) override;
+  void drawArc(const SkRect& oval_bounds,
+               SkScalar start_degrees,
+               SkScalar sweep_degrees,
+               bool use_center) override;
+  void drawPoints(PointMode mode,
+                  uint32_t count,
+                  const SkPoint points[]) override;
+  void drawVertices(const DlVertices* vertices, DlBlendMode mode) override;
+  void drawImage(const sk_sp<DlImage> image,
+                 const SkPoint point,
+                 DlImageSampling sampling,
+                 bool render_with_attributes) override;
+  void drawImageRect(
+      const sk_sp<DlImage> image,
+      const SkRect& src,
+      const SkRect& dst,
+      DlImageSampling sampling,
+      bool render_with_attributes,
+      SrcRectConstraint constraint = SrcRectConstraint::kFast) override;
+  void drawImageNine(const sk_sp<DlImage> image,
+                     const SkIRect& center,
+                     const SkRect& dst,
+                     DlFilterMode filter,
+                     bool render_with_attributes) override;
+  void drawAtlas(const sk_sp<DlImage> atlas,
+                 const SkRSXform xform[],
+                 const SkRect tex[],
+                 const DlColor colors[],
+                 int count,
+                 DlBlendMode mode,
+                 DlImageSampling sampling,
+                 const SkRect* cull_rect,
+                 bool render_with_attributes) override;
+  void drawDisplayList(const sk_sp<DisplayList> display_list,
+                       SkScalar opacity = SK_Scalar1) override;
+  void drawTextBlob(const sk_sp<SkTextBlob> blob,
+                    SkScalar x,
+                    SkScalar y) override;
+  void drawShadow(const SkPath& path,
+                  const DlColor color,
+                  const SkScalar elevation,
+                  bool transparent_occluder,
+                  SkScalar dpr) override;
+
+  // Indicates if the attributes are set to values that will modify the
+  // destination. For now, the test only checks if there is a non-transparent
+  // color set.
+  bool will_draw_ = true;
+
+  bool did_draw_ = false;
+};
+
+}  // namespace flutter
+
+#endif  // FLUTTER_DISPLAY_LIST_DL_OP_SPY_H_